Hello Datz_cozee75,

Consider what the following assignments do:

my ($rvars) = shift;
my %vars = %$rvars;
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The first line shifts an argument off the call stack and copies it to the lexical variable $rvars. So far, so good. But then the second line dereferences $rvars as a hash (using the %{ ... } dereferencing syntax), and copies the contents of that hash into the new lexical hash variable %vars. From this point on, %vars is a local copy of what was in %$vars when the subroutine was called. Any changes made to %vars remain local to the subroutine, and have no effect on the contents of the original hash. So when next_file() is called, it receives $rvars as its first argument, but the hash to which that variable refers has no key named ref_alpha, so the attempt to access it on line 116 fails and produces the error message you are seeing.

But why do you want to make a copy of the hash %$rvars? Just remove the variable %vars, and access the “master hash” directly:

my ($rvars) = shift;
...
my $path1 = $vars->{"to_images"};
my $path2 = $vars->{"to_magick"};
...
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Study perlreftut and get comfortable with Perl’s dereferencing syntax. It can be quite confusing at first, but if you persevere there will come a point where it will start to “click”, and then you’ll never look back!

Hope that helps,